Mixture having antitumor activities

Abstract

A purified hot-water extract from Mycobacterium bovis (BCG vaccine) has been found to have significant antitumor activity against a mouse bladder tumor model and a murine sarcoma in vivo, but not in vitro. The material, termed PS1A1, has an approximate molecular weight of between 60 and 90 kDa, is freely soluble in water, but has low solubility in acetone or ethanol, and is remarkably heat-stable.

We claim: 
     
       1. A polymer extract having antitumor activity obtained from Mycobacterium bovis BCG (TICE substrain) comprising a plurality of α-D-glucopyranosyl-(1-6)-α-D-glucopyranose units and at least one α-D-glucopyranosyl-(1-4)-α-D-glucopyranose unit wherein the polymer has a molecular weight of from between 65 and 87 kDa. 
     
     
       2. The polymer extract of claim 1 having a molecular weight of between 64.5 and 67 kDa. 
     
     
       3. The polymer extract of claim 1 wherein said polymer extract possesses a molecular weight of approximately 67 kDa. 
     
     
       4. The polymer of claim 1 having the structure: ##STR2## 
     
     
       5. The polymer extract of claim 1 wherein the extract is an aqueous extract. 
     
     
       6. A pharmaceutical substance possessing antitumor activity comprising the polymer extract of claim 1 and a pharmaceutically acceptable carrier.